Thread

ABSTRACT

A stiffening thread for use in increasing the durability of a crease in a panel of fabric comprises at least one ply of thermofusible material having a melting point between 75° C. and 125° C. and at least one carrier ply of material which is not thermofusible, having a melting point above 125° C., wherein the at least one thermofusible ply is a monofilament thermofusible ply.

FIELD OF THE INVENTION

The present invention relates to thread, typically of a kind that may beused in the manufacture of garments in which it is desired to constructdurable creases.

DESCRIPTION OF RELATED ART

Garments with such, creases are known per se. One way in which durablecreases are manufactured is by the provision of a substance in theregion of the crease which acts to create a degree of rigidity in andmutual adherence between fibres of the fabric at the apex of andimmediately adjacent the crease. The action of the substance on thefabric ensures that the crease remains present in the fabric for longerand in a more pronounced way.

Such a substance may have the form of a resin in the region of thecrease applied in the region of the crease, which is then melted byheat. Such a manner of creating a durable crease is one used bySupercrease Ltd under the registered trade mark SUPERCREASE.

SUMMARY OF THE INVENTION

A first aspect of the present invention relates to thread which may beused to achieve such creases and which comprises a thermo-fusibleelement. A further aspect of the present invention relates to a methodof generating a crease in a panel of fabric using a thermofusiblethread.

According to embodiments of the present invention, a durable crease isapplied to a panel of fabric by laying a stiffening thread along acrease line of the fabric panel. The stiffening thread comprises one ormore elements of thermofusible material. Once the stiffening thread hasbeen correctly positioned, the fabric panel is the folded along thecrease line and heat and pressure is applied to the fabric panel in theregion of the crease. The application of heat causes the thermofusiblematerial of the thread to melt. On melting the thermofusible materialbecomes mobile and flows to some degree through the fibres of the panel.The extent of this flow is amplified by the pressing action. The effectof the pressure is to force the hot, fluid thermofusible material topropagate through the fibres of the panel. Once the melted fusiblematerial within the fabric has cooled and thus solidified once again, itacts to add rigidity to the fibres of the fabric and, additionally, byfilling the spaces between them, to assist in retaining the relativeconfiguration of those fibres. This, in turn, makes the fabric in thepanel in the region of the crease line significantly more rigid whichresults in the crease itself having greater durability.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be described, by way ofexample, and with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a panel of fabric in which a durablecrease is to be created according to an embodiment of the presentinvention;

FIG. 2 shows constructions of stiffening thread according to anembodiment of the present invention;

FIG. 3 shows further constructions of stiffening thread according anembodiment of the present invention;

FIG. 4 shows yet a further construction of stiffening thread accordingan embodiment of he present invention;

FIG. 5 is a perspective view of a part of a method of manufacturing apanel with a durable crease according to an embodiment of the presentinvention;

FIG. 6 is a perspective view of a panel of fabric after fixing of thestiffening thread according to an embodiment of the present invention;

FIG. 7 is a perspective view of an apparatus used in a first embodimentof method according to the present invention;

FIG. 8 is a side view of the apparatus of FIG. 7;

FIG. 9 is a view on IX-IX in FIG. 7;

FIG. 10 is a detail of FIG. 9; and

FIGS. 11 to 14 are side views of apparatus used in a second embodimentof manufacture according to the present invention at various stages inthe process of manufacture.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIG. 1, a panel 10 of fabric has a crease line 12extending within it which then defines two sides 14A and B to the panel.According to one embodiment of the present invention the panel 10 is ofa man-made material which may habitually washed in water, though this isnot essential and natural fabrics, such as wool or linen may also beused. The crease line is typically created initially by pressing with ahot iron (or the industrial equivalent in the case of large scalemanufacture of garments using such panels). A habitual problem withcreases created in this way is that any garment in which such a creaseis created will, inevitably during the course of being worn, besubjected to stresses and strains in the fabric which will act todegrade the integrity of the crease line, leaving it less sharplydefined. This will, in turn, leave the garment in which the crease iscreated looking less smart.

According to an embodiment of the present invention, a stiffening thread20 is laid along the crease line 12 of the fabric panel 10. The thread20 comprises one or more elements of thermofusible material. Thestiffening thread is then fixed to the panel by stitching. Preferably,the fixing stitch is a stitch configuration which can be readilyunpicked, for example a stitch which is capable of being unpicked bysimply pulling along its length once the stitch pattern has been brokenat one point. In one preferred embodiment, the fixing stitch is achainstitch. Once the thread 20 has been attached to the fabric panel10, the panel is the folded along the crease line 12 and heat andpressure is applied to the fabric panel. This can be done by ironing oran equivalent industrial process such as by means of a heat press. Theapplication of heat causes the thermofusible material of the threat tomelt. On melting the thermofusible material becomes mobile and flows tosome degree through the fibres of the panel 10. The extent of this flowis amplified by the pressing action. The effect of the pressure is toforce the hot, fluid thermofusible material to propagate through thefibres of the panel 10. Once the melted fusible material within thefabric has cooled and thus solidified once again, it acts to addrigidity to the fibres of the fabric and, additionally, by filling thespaces between them, to assist in retaining the relative configurationof those fibres. This, in turn, makes the fabric in the panel 10 in theregion of the crease line significantly more rigid which, in turn,causes the crease itself have greater durability.

The stiffening thread 20 comprises, as has been stated previously, atleast an element which is made of thermofusible material. Thermofusiblematerial is known per se. One example series of thermofusible threadsmanufactured by Grilon EMS of Switzerland, under the trade markdesignation ‘K’, such as, for example, K85. The stiffening thread 20 mayfurther include one or more elements which are not thermofusible.Examples of such combination threads are also manufactured by Grilon EMSof Switzerland, under the trade mark designation ‘C’, such as, forexample, C85.

According to a preferred embodiment of the present invention a threadfor use in generating a durable crease comprises a plurality of pliedyarns, at least one of which comprises filaments which are thermofusibleat a first temperature and at least a further one of which is a carrierply providing structural integrity to the thermofusible ply.

Referring to FIG. 2, the plies of the thermofusible material may beplied in a traditional manner by twisting them around each other in ananti-clockwise direction (an S twist) or a clockwise direction (a Ztwist), Where the individual plies are multifilament, the individualfilaments of those plies are typically twisted in the opposite directionto the ply direction to counteract the torque and provide a plied threadwhich is torque neutral, or nearly torque neutral.

Referring to FIG. 3, according to an alternative embodiment ofstiffening thread, where there are three plies, the or each carrier plyand the or each thermofusible ply are braided. One preferred embodimentcomprises a single carrier ply and two thermofusible plies.

Referring to FIG. 4, in yet a further embodiment, the stiffening threadis of wrapped construction, having a core ply around which is wrappedone (in the illustrated embodiment) or more cover plies 42 which aretypically of lower grist.

In one embodiment of stiffening thread according to the presentinvention, the stiffening thread comprises at least one thermofusibleply, having a melting point between 70 and 120° C. and of between 200and 600 Denier and preferably 400 Denier, and at least one carrier plywhich is not thermofusible and having a grist of between 100 and 400Denier. In one preferred embodiment the carrier ply has a grist of 270Denier. Preferably the carrier ply has a melting point above 120° C.Preferably, the thermofusible ply is a monofilament ply thoughmultifilament may also be used.

A preferred embodiment of stiffening thread comprises a 3 ply thread ofwrapped construction. The core of the stiffening thread is the carrierply, which is of polyvinyl alcohol (PVA) of 270 Denier. The threadfurther comprises two cover plies, wrapped around the core, each beingmonofilament yarns of polyamide having a melting point of 110° C., eachof which is of grist 400 Denier. The PVA core is soluble in water at atemperature of 30° C.

In an alternative embodiment, the core of the stiffening thread is ofpolyester corespun or staple yarn having a grist 225 Denier.

In yet a further alternative, the or each thermofusible ply has amelting point of 85° C.

Further embodiments of stiffening thread, of whatever threadconstruction include

Two thermofusible plies having a grist of 200 Denier and a carrier plyof 120 Denier Two thermofusible plies having a grist of 600 Denier and acarrier ply of 400 Denier

The application of the various modifications of any aspect of anyembodiment such as for example, thread construction) are not limited tothe embodiments in connection with which they are first disclosed (suchas for example, the grist value, melting point and construction of theindividual plies) and each such modification is hereby explicitlydisclosed in con unction with each thread construction.

As mentioned above, once the garment is manufactured, including theinsertion of the stiffening thread 20 running substantially parallel tothe crease line 12, the garment is pressed and, as a result of the heatand pressure applied during the pressing process, a crease is createdwithin the garment whose durability is increased. Use of one or moremonofilament thermofusible plies have been found to provide improveddurability of the resultant crease by comparison to the use ofmultifilament plies of thermofusible material. This is thought to bebecause of the smaller degree of propagation of the melted thermofusiblematerial in the case of monofilament plies, which therefore provides agreater concentration and stiffness in the immediate region of thecrease. Where a lower stiffness is required, for example in the case ofa finer fabric in the garment providing greater fabric mobility,multifilament thermofusible plies or lower grist plies may be used.

After the pressing process is finished and the garment has cooled, thecarrier ply of the stiffening thread has served its purpose. Where thatcarrier ply is of PVA typically, to reduce costs, a PVA ply of a singlecolour (typically white though not essentially so), is used rather thanmatching the colour of the carrier ply to the fabric colour. This meansthat the carrier ply will be visible unless the garment is of the samecolour. However, because the carrier ply is of PVA, and PVA is watersoluble, the carrier thread will, during a washing process, dissolve inthe water used to wash the garment. It will, therefore, effectively, bewashed out of the garment during the first and few subsequent washingoperations, leaving only the now fused and distributed thermofusiblethread which maintains the durability of the crease.

In an alternative embodiment of thread according to the presentinvention, the core of the wrapped thread is of polyester.

An embodiment of the present invention provides a stiffening thread foruse in increasing the durability of a crease in a panel of fabric, thethread comprising at least one ply of thermofusible material having amelting point between 75° C. and 125° C. and at least one carrier ply ofmaterial which is not thermofusible, having a melting point above 125°C., wherein the at least one thermofusible ply is a monofilamentthermofusible ply. Preferably, the melting point of the thermofusibleply is between 80° C. and 115° C.

Another embodiment of the present invention provides a stiffening threadfor use in increasing the durability of a crease in a panel of fabric,the thread comprising at least one ply of thermofusible material havinga melting point between 75° C. and 125° C. and at least one carrier plyof material which is not thermofusible, having a melting point above125° C., wherein the thread is of wrapped construction with the carrierply providing a core and the thermofusible ply being wrapped around thecarrier ply. Preferably, the thread comprises two thermofusible pliesand one carrier ply.

Another embodiment of the present invention provides a stiffening threadfor use in increasing the durability of a crease in a panel of fabric,the thread comprising a ply of thermofusible material having a meltingpoint between 75° C. and 125° C. and at least one carrier ply ofmaterial which is not thermofusible, having a melting point above 125°C., wherein the thread is of braided construction. Preferably, thethread comprises two thermofusible plies and one carrier ply.

Another embodiment of the present invention provides a stiffening threadfor use in increasing the durability of a crease in a panel of fabric,the thread comprising a ply of thermofusible material having a meltingpoint between 75° C. and 125° C. and at least one carrier ply ofmaterial which is not thermofusible, having a melting point above 125°C., wherein the carrier ply is of polyvinyl alcohol (PVA) and is solublein water at temperatures of above 40° C. Preferably the carrier ply issoluble in water at temperatures of above 30° C.

Details of the manufacture of a crease with improved durability will nowbe described with reference to FIGS. 5 and 6. Referring now to FIG. 5,the panel 10 which is supported on a sewing table lies under the presserfoot 50 of a sewing machine. A stiffening thread 20 is drawn from a reelor cone or other suitable thread carrier (not shown) under the panel 10.A guide 60 for the stiffening thread 20 comprises a plate 62 by whichthe guide is fixed in position on the table while the thread 20 passesthrough a semi-circular guide tube 64 which serves to fix the relativeposition of the panel 10 and the thread 20 as the thread is drawn underthe presser foot 50. The needle 66 of the sewing machine then fixes thestiffening thread to the panel 10 by stitching a fixing stitch, formedfrom fixing thread 68, In the illustrated embodiment a lockstitch isshown. Preferably, the fixing stitch is of a configuration which caneasily be unpicked once broken at one point along its length. In oneembodiment the fixing stitch configuration is a chain stitch.

According a further embodiment, the fixing stitch is stitch type 402,being a twin needle chainstitch which further requires a looper threadfor fastening. Referring to FIG. 6 the stiffening thread 20 is shown,fixed to the panel 10 by the fixing stitch 70.

Once the stiffening thread has been fixed to the panel, the panel isthen folded along the crease line 12 and pressed along the crease line(which in FIG. 6 is then coincident with the fixed position of thestiffening thread 20). This is typically performed using an open pressor other suitable form of pressing equipment which applies both pressureand heat to the panel in a folded configuration. Typically, steam oranother medium may be used additionally to conduct heat through thepanel during the pressing process to assist in generating a crease and,additionally, to melting the thermofusible material. After formation ofthe crease and melting of the thermofusible material, the panel is thenallowed to cool and the thermofusible material then sets in the mannerand having the effect described above. In the illustrated embodiment thestiffening thread is coincident with the crease line; but laying thethread substantially coincident (for example offset to one or other sidefor example) is acceptable provided that an improved durability in thecrease can be obtained.

When the panel has cooled and the thermofusible material has set, thefixing stitch has then served its purpose and is removed. Preferably,the fixing stitch has a configuration which is easily unpickable, suchthat breaking it at one point along its length then permits the thread66 used for the stitch then simply to be pulled out in a singleoperation. One preferred embodiment of fixing stitch is a chainstitch.

Further embodiments of the present invention, will now be described inwhich the stiffening thread is positioned and the fabric panel creasedalong a line coincident with the location of the thread position, andheated. Referring now to FIGS. 7 and 8, according to a first preferredembodiment, this is achieved by guiding the thread into the correctalignment with respect to the fabric panel (shown in FIG. 9) and thenpassing the guided thread through a sequence of mangling rollers whilstapplying heat to the thread to cause the thermofusible elements of it tomelt. In implementing various embodiments it has been found that it isnot necessary to fix the stiffening thread to the fabric panel, forexample by stitching, prior to folding, pressing and heating the panelto create the durable crease.

A suitable apparatus, shown without the fabric panel or stiffeningthread, includes a planar bed 210 upon which the fabric panel in which acrease is to be created is laid and which supports that panel. Thefabric panel may incorporate guide marks or other indicia indicating thedesired location of the crease line, though this is not essential. Aguide groove 212 extends along the bed 210. In use, an operator willalign the fabric panel so that the guide groove 212 extendssubstantially coincident with the desired position of the crease line onthe panel. Where the panel carries marks, the marks on the fabric panelmay advantageously be aligned with the groove 212. A pair of motoriseddrive rollers 214A,B, journaled about a substantially vertical axis,pinch and grip a fabric panel and cause the panel to move in thedirection of arrow A in FIG. 7. Further rollers 220, assist with thisoperation while heating the panel, the purpose and operation of whichwill be subsequently described.

Referring now additionally to FIGS. 9 and 10, a pilot member whosefunction is to deform the panel of fabric to create a fold which willeventually become a durable crease is, in the present embodiment,provided by guide foot 216, mounted on an arm 218. The guide foot 216urges the panel 226 into the groove 212 as the panel is drawn past theguide foot 216 by the action of the rollers and, in so doing, creates afold 228 in the panel 226 at the desired position of the crease line.

Referring now additionally to FIGS. 9 and 10, the base of the foot 216has a groove 222, which is shaped so as to provide a guide along whichthe stiffening thread 224 can be drawn and retained. This ensures thatonce the fabric panel 226 has had a fold applied 228 to it, because thethread 224 is retained on the guide foot 216 which itself is creatingthe fold 228, the thread 224 is retained coincident with the fold 228 inthe panel enters the rollers 214, 220 in the correct alignment withrespect to the fold 228 in the panel 226 of fabric (as long as thefabric panel is correctly aligned with the groove 212). Thus, the fold228, which is the precursor to the crease line, is formed coincidentwith the location of the stiffening thread 224 relative to the panel 226prior to the panel being pinched by the drive rollers 214A,B.

After passing through the mangle provided by drive rollers 214A,B, thepinched (and therefore folded by virtue of the pinching) panel 226 isthen fed through a pair of heating rollers 220A,B.

Heat applied by the heating rollers causes the fusible component of thestiffening thread to melt with the consequence of producing a durablecrease as discussed above. According to one preferred embodiment theheated rollers 220 are also motorised and rotate fractionally fasterthan the guide rollers 214 so as to stretch the fabric. This serves toavoid snagging and, additionally, provides better dispersion of thefusible components of the melted thread into the fibres of the fabricpanel. In a modification, a single set of rollers providing drive andheating simultaneously is provided. In yet a further modification, therollers 220 either serve merely for guidance or are omitted and hot airis passed through the fold in the panel to melt the fusible thread.

The stiffening thread 224 will typically be drawn off a reel containinga longer length and is cut following passage of the panel through therollers 214, 220 then subsequently trimmed if required.

The foregoing embodiment of the present invention provides a method ofapplying a durable crease to a panel of fabric (which may be used in agarment) comprising the steps of: placing a composite thread comprisingat least one ply of thermofusible material upon the panel; applying afold to the panel whilst locating the thread; and applying heat to thepanel thereby to melt the at least one thermofusible ply. Preferably thepanel and stiffening thread are fed into a folding mechanismsimultaneously substantially along the direction of the crease.Preferably, the feeding of the panel and thread takes place by theaction of mutually opposing rollers which grip the sides of the paneland draw the panel and thread with a mangling action.

The foregoing embodiment enables creases of any required length to becreated as desired.

A further embodiment of manufacturing method will now be described byreference to FIGS. 11 to 214. Referring to FIG. 11, a pivoting heatedpress includes two pressing plates 260A, B. The plates 260A,B eachcomprise a structural bed 262, typically of a conductor such as metal,upon which is coated a layer 264 of material of some resilience. Thelayers 264 provides some ‘give’ when the fabric panel is pressed betweenthem. Pressing is performed by a pivoting action of the plates generallyabout a point or on a locus situated at their lower end. The precisenature of the pivoting action may vary in that there may be a strictpivoting of the plates 260A, B about a point in the region of their baseor the apparatus may be constructed to provide a more arcuate pivotingpath which, therefore, additionally involves some translation. A furtherelement of the apparatus is the pilot member which, in this embodimentgenerates the fold in the fabric panel whilst locating the threadrelative to the panel and, at the same time provides the motive force bymeans of which the panel is drawn into the space between the pressingplates 260. In the present embodiment the pilot member is provided by ashaping blade 270, which is mounted for translational projection andretraction between the plates. Projection of the blade 270 into thespace between the plates 260A,B serves to position the fabric panelprior to closing of the plates 260A,B for a pressing operation. Theblade is typically made of stainless steel and has a planar constructiontapering at its lower edge 272. A retaining groove 274 in the lower edgeholds the stiffening thread 280 relative to the blade 270 so that, whenthe blade 270 is projecting into the space between the plates 260A,B todraw in the fabric panel 290 prior to a pressing operation, the thread280 is correctly located relative to the blade 270 and therefore,relative also to the fold which the drawing action of the blade 270generates The groove therefore ensures that the stiffening thread 80remains in the proper position with respect to the fabric duringpressing.

Referring now additionally to FIG. 12, a pressing operation commenceswith the fabric panel 290 being placed across the upper ends of theplates 260A, B when in the open position. The blade 270 is then moveddownwards to project into the space between the plates 260 while,simultaneously, pivoting of the plates into the closed position thenstarts to occur. The projecting motion of the blade 270 causes a fold tobe created in the fabric panel, the apex 296 of which is coincident withthe position of the stiffening thread 280, and the fabric panel 290 tobe drawn into the space between the closing plates 260A,B.

When full projection of the blade 270 has occurred, the panel 290 hasthen been fully drawn by the blade 270 into the press as shown in FIG.12, Further dosing of the plates then serves initially to grip the panel290 and, as a result, locates the thread 280 relative to the panel 290by the gripping action of the plates 260 by virtue of the frictionbetween the panel 290 and the thread as shown in FIG. 13. The locationof the thread 280, being substantially coincident with the apex 296 ofthe fold whose location was determined initially by the blade 270 and,upon gripping of the panel by the plates, is maintained by the frictionbetween the panel 290 and thread 280 arising as a result of the grippingaction. Subsequent to this, the blade 270 then starts to retract. Theplates 260A,B continue to close fully around the panel as the blade isretracted further. The resilience of the covering layer 264 providingthe necessary give to enable gripping of the apex 292 of the panel 290and retaining the stiffening thread 280 within the panel 290 at thelocation where the crease is to be created and, simultaneously, fullretraction of the blade 270 to occur whilst the panel 290 retains thestiffening thread 280 in the correct place under the pressing action ofthe plates 260. This is shown in FIG. 14, The pressing and heatingaction of the plates 260A,B then cause the creation of the crease and,simultaneously, melting of the thermofusible element or elements of thestiffening thread 280.

Typically, the thread may be drawn into and along the retraining groove274 from a reel (not shown) prior to pressing and is then, once fullprojection of the blade 270 and gripping of the panel 290 by the plates260A,B has occurred, is cut from the reel.

The foregoing embodiment provides a method of applying a durable creaseto a panel of fabric (which may be used in a garment) comprising thesteps of: placing a composite thread comprising at least one ply ofthermofusible material upon the panel; applying a fold to the panelwhilst locating the thread; and applying heat to the panel thereby tomelt the at least one thermofusible ply. Preferably, the panel is drawninto a space between a pair of pressing plates by a blade in a directionsubstantially perpendicular to the direction of the crease.

The foregoing embodiment enables creases of significant depth withregard to the size of the fabric panel to be created.

1. A stiffening thread for use in increasing the durability of a creasein a panel of fabric, the thread comprising at least one ply ofthermofusible material having a melting point between 75° C. and 125° C.and at least one carrier ply of material which is not thermofusible,having a melting point above 125° C., the thread further comprising atleast one characteristic selected from the group consisting of: a) theat least one thermofusible ply is a monofilament thermofusible ply b)the thread is of wrapped construction with the carrier ply providing acore and the thermofusible ply being wrapped around the carrier ply c)the carrier ply is of polyvinyl alcohol (PVA) and is soluble in water attemperatures of above 40° C. d) the thread is of braided construction.2. A thread according to claim 1 comprising at least two thermofusibleplies.
 3. A thread according to claim 1 wherein the melting point thethermofusible material is between 80° C. and 125° C.
 4. A threadaccording to claim wherein the melting point of the thermofusiblematerial is 85° C.
 5. A thread according to claim 3 wherein the meltingpoint of the thermofusible material is 110° C.
 6. A thread according toclaim 1 wherein each thermofusible ply has a grist of between 100 and600 Denier.
 7. A thread according to claim 1 wherein each carrier plyhas grist of between 75 and 400 Denier.
 8. A thread according to claim 1having a carrier ply of grist between 220 and 280 Denier and athermofusible ply of between 400 and 500 Denier.
 9. A thread accordingto claim 1 wherein the thermofusible ply is of monofilamentconstruction.
 10. A thread according to claim 1 wherein the thread is ofbraided construction.
 11. A thread according to claim 1 wherein thethread is of wrapped construction with the carrier ply providing a coreand the thermofusible ply being wrapped around the carrier ply.
 12. Athread according to claim 1 wherein the carrier ply is of PVA and issoluble in water at temperatures of above 40° C. A thread according to 2wherein the PVA is soluble in water at temperatures above 30° C.